General

Girl being nice or Flirty?

Okay how can you tell if a girl is being nice or just flirty?

My situation (if anyone is curious):
During lunch at my job (working there for 3 months now) a girl came up to me who i just had small talk with but never got her name finally walked up to me and introduced herself asking why i was eating by myself. Baffled by her looks i blatantly blurred out "because i got no friends " (I do got friends but i was at a lost for words during that moment it was very unexpected). She invited me over to eat and told me to sit RIGHT next to her with some other co workers. We all talked for about 10 minutes before the other co workers had to go back to work. So it was just me and her talking and some other joined in after a while. Getting to the point soon she had to return to work as well. We were well into a conversation about ourselves and she was walking backwards slowly, still keeping the conversation alive by asking me questions such as "where i am from and my nationality". Judging from her walking backwards it seemed like she just wanted to go back to work already so i wrapped up the question and said an awkward "cya". She replied with a different tone of voice "Do you want me to leave?" which i replied "no, i dont actually". Then she asked if i would like to talk to her all day and i replied with a yea. She said to come see her more often at her department.

TLDR; hot chick introduced herself and asked me to sit next to her for lunch, we talked and it seemed like she didnt want to leave. Told me basically to talk to her more often.

i dunno if she was being friendly or flirting with me. After she said to see her more the other 2 coworkers in front of me raised there eyebrows and looked at each other. It was like a "ohhhh snapppp" kinda look.